废水处理技术生命周期分析基本概念初探

运用生命周期分析(LCA)可对不同的废水处理工艺方案进行选择和比较，优选出资源消耗和环境污染最少的实施方案。其技术关键在于如何将ISO 14040等国际标准中规定的LCA方法学正确地应用至各种废水处理工艺的相对比较。本文对LCA应用于废水处理技术的一些基本概念进行了定义和探讨，其中包括废水处理系统的定义；废水处理厂的生命周期；废水处理工艺的功能、功能单位和基本流等。     

低有机负荷下三槽式氧化沟运行参数的调整实践

由于唐山某污水处理厂进水的有机负荷远低于设计运行进水条件,致使三槽氧化沟运行不正常。针对这种情况,对低有机负荷状态下三槽式氧化沟的运行参数进行了调整,探索出了低有机负荷状态下三槽式氧化沟的运行模式。     

Setting the stage for the review of the international estimate of short-term intake (IESTI) equation

ABSTRACT

In the framework of setting Maximum Residue Limits (MRLs) for pesticides, both chronic and acute health risks to consumers arising from the long-term and short-term dietary exposure to pesticide residues have to be assessed. The current internationally harmonized approach for assessing the acute dietary exposure is based on deterministic methods for calculating the IESTI (International Estimate of Short-Term Intake). Recently, it became apparent that the IESTI approach needs a revision in the light of new scientific and political aspects. The main reasons that require this review were the lack of an international harmonization of the methodology which implies trade barriers as well as difficulties in risk communication concerning the public trust in regulatory systems. The most recent milestone in the scientific debate on a possible revision of the IESTI equation was an international scientific workshop held in Geneva in September 2015. The main objectives of this meeting were the re-evaluation, and where possible, the international harmonization of the input parameters for the IESTI equations as well as the equations themselves. The main recommendations from the workshop were (i) to replace the highest residue and supervised trials median residue with the maximum residue limit (MRL), (ii) to use a standard variability factor of three, (iii) to derive the P97.5 large portion value from the distribution of consumption values of dietary surveys expressed as kg food/kg bw/d, and (iv) to remove the commodity unit weight from the equations. In addition, the application of conversion factors and processing factors was addressed. On the initiative of the (World Health Organization) WHO Collaborating Centre on Chemical Food Safety at the National Institute for Public Health and the Environment (RIVM), the Netherlands, an international working group with members from the French Agency for Food, Environmental and Occupational Health and Safety, France (ANSES), Australian Pesticides and Veterinary Medicines Authority, Australia (APVMA), German Federal Institute for Risk Assessment, Germany (BfR), Chemical Regulation Division, the United Kingdom (CRD), European Food Safety Authority (EFSA), and RIVM, the Netherlands was formed after the IESTI workshop to conduct a comprehensive impact assessment of the proposed changes of the IESTI equations.     

基于数量视角的耕地保护政策绩效评价

耕地保护政策的绩效评价是我国粮食安全及土地调控的重要课题。本文基于数量保护的视角,采用数据包络分析法(DataEnvelopment Analysis,简称DEA)评价了我国2000-2007年的耕地保护政策绩效,测度对象主要为耕地总量动态平衡、土地用途管制、耕地执法监管政策。研究结果显示,耕地保护政策在数量保护上具有总体效率高(2002年除外)、规模效率递增或保持、纯技术效率高的表征,但是,规模效率、纯技术效率与总体效率不能很好拟合且三项效率的综合具有分层性,只有耕地总量动态平衡达到了最佳产出。进而得出结论:2000-2007年,耕地保护政策取得了耕地总量平衡、耕地基本数量维持、建设占用耕地趋缓、耕地违法减少的显著效果,然而,耕地保护政策绩效的年度差异、政策时滞及体制等影响因素的复杂、投入和产出的部分饱和亦表明绩效的不充分。为促进我国耕地保护政策绩效的提升,提出强化土地利用总体规划作用、建立耕地保护责任制度等建议,并对进一步研究作了展望。     

爆炸荷载作用下砌体结构响应的有限元分析

对墙体模型进行简化,用单个混凝土砖块宽度的墙来代替所要分析的整面墙,并采用有限元分析软件LS-DYNA对砌体墙的破坏模式进行数值模拟分析。LS-DYNA的数值模拟结果显示,混凝土砌体墙在不同爆炸荷载作用下会发生不同程度的破坏,破坏的产生首先从墙体中部开始;随着爆炸荷载峰值的提高,砌体墙的破坏逐渐由中间向两端发展,当爆炸荷载峰值压力达到0.36 MPa及以上时,墙体会发生破坏,有块体飞出,并在重力作用下发生倒塌。数值模拟的结果与文献提供的试验结果比较吻合。     

The Avoidance Responses of Daphnia magna to the Exposure of Organophosphorus Pesticides in an On-Line Biomonitoring System

In this study, avoidance behavior of the freshwater cladoceran Daphnia magna Straus was used as indicator to assess the early stress of accidental organophosphorus pesticide (OP) contamination. The movement behavior was detected by a multi-species biomonitoring system. There was obvious concentration–response relationship between the OP stress and the behavioral response even at sublethal exposure. A rising OP stress resulted in a significant decrease of response time to escape (RTE; p<0.05). In comparison of different OPs, it was found that there was a power regression between RTE and the toxic unit of OPs. Therefore, the avoidance behavior of D. magna was a sensitive indicator of sublethal OP stress, and the power relationship could be used to predict the early warning thresholds of more OPs in the on-line biomonitoring system.     

可拆卸式橇装增压集成装置在长庆油田中的应用

为了改善长庆油田增压点主要生产设备橇装增压集成装置加热区长时间运行易结垢、维护困难、检修成本高等问题,进行了"可拆卸式橇装增压集成装置"的研制工作。可拆卸式橇装增压集成装置的加热盘管和火筒可直接从装置端部抽出,在加热盘管和火筒遭到腐蚀或结垢破坏后,能够快速进行检修、维护或更换,有效延长了装置整体的使用寿命。"可拆卸式橇装增压集成装置"已在长庆油田得到推广应用。     

Assessment of exposure to PCB 153 from breast feeding and normal food intake in individual children using a system approach model

Investigators have typically relied on a single or few discrete time points as measures of polychlorinated biphenyl (PCB) body burden, however health effects are more likely to be the result of integrative exposure in time, optionally expressed as an area under the time curve (AUC) of PCB serum concentration. Using data from a subgroup of 93 infants from a birth cohort in eastern Slovakia—a region highly polluted by PCBs—we fit a system type model, customized to our longitudinal measures of serum PCB concentrations in cord, 6, 16, and 45 month blood specimens. The most abundant congener, PCB 153, was chosen for modeling purposes. In addition to currently used methods of exposure assessment, our approach estimates a concentration time profile for each subject, taking into account mean residence time of PCB 153 molecules in the body, duration of breast feeding, hypothetical PCB 153 concentration in steady-state without breast feeding and alternately without normal food intake. Hypothetical PCB 153 concentration in steady-state without normal food intake correlates with AUC (r = 0.84, p < 0.001) as well as with duration of breast feeding (r = 0.64, p < 0.001). It makes possible to determine each subject’s exposure profile expressed as AUC of PCBs serum concentration with a minimum model parameters. PCB body burden in most infants was strongly associated with duration of breast feeding in most, but not all children, was apparent from model output.     

石灰石/石膏湿法脱硫系统单耗分析及节能方向

建立了石灰石/石膏湿法烟气脱硫系统单耗分析模型,以三河电厂350MW机组为例,分析了脱硫系统单耗在各设备及系统的分布情况,探讨湿法烟气脱硫系统的节能方向。     

遥感在环境影响评价中的应用——以大清公路为例

本文以遥感为技术手段,利用ERl、ASⅢAGINE8.5和FRAGSTATS3.3软件针对项目区在景观总体格局和各类型斑块两个层次计算出十几种景观指数,对该区域的景观格局分布做出了较为全面的定量分析.结果表明:草地景观面积最大,斑块数最多,是评价区的基质.乔木林地在各项指数分析中均较低.文中探讨了遥感与地面调查的优缺点,得出结论:以遥感技术为手段,结合地面调查是评价区域生态环境的有效工具.